The invention relates to an assembly consisting of a vehicle door, an A-pillar of a vehicle and an inflatable gas bag.
Gas bags have a proven record of success in restraint systems to protect the vehicle occupant from injuries due to, for example, the vehicle being involved in a head-on collision. To offer protection also in the case of a side-impact collision or toppling of the vehicle, side gas bags are employed. Such gas bags are known which prior to deployment are accommodated in the roof structure or A-pillar of the vehicle and are stabilized via arresting devices to the vehicle parts. Likewise known are gas bags which prior to deployment are accommodated in the vehicle door and may be supported deployed by the B-pillar of the vehicle and/or windowsill.
When the vehicle is involved in an accident it is very often the case that the side windows of the vehicle are shattered and thus no longer afford any supporting effect so that a side gas bag needs to not only deplete the movement energy of the vehicle occupant in avoiding injury but also to prevent the vehicle occupant, his head or hands from being catapulted outwards from the vehicle.
On vehicles having no roof contour, especially convertibles, this protection is most important. At the same time, however, difficulties materialize in providing the gas bag with adequate stability, due to the lack of the vehicle roof structure, since it is obvious that conventional gas bags deploying from the door and supported by the B-pillar, roof or window frame cannot be made use of in this case.
The object of the invention is to provide a gas bag for vehicles having no roof contour which is capable of preventing the vehicle occupant from being catapulted outwards. For this purpose in an assembly consisting of a vehicle door, an A-pillar of a vehicle and an inflatable gas bag the gas bag in an inflated condition is supported by the vehicle door and in a region of the A-pillar of the vehicle. The internal overpressure exceeds 105 Pa (14.5 psi)in at least one part of the inflated gas bag. The gas bag gains the necessary stability from the support in the region of the A-pillar and preferably at the windowsill, i.e. by the gas bag being supported either by the A-pillar itself or by the section of the door frame located in the vicinity of the A-pillar. This stabilizes the gas bag in the region between windowsill and A-pillar. The high internal overpressure in the gas bag ensures that also the exposed, i.e. non-supported portion of the gas bag does not give way outwards in cushioning a vehicle occupant or part of his body.
Advantageously, the gas bag is fabricated so as to be gas-tight, i.e. the material of the gas bag itself being gas-tight and the gas bag having no gas-exit ports. Since the compressed gas is unable to escape from the gas bag, the gas bag maintains its shape and the high internal overpressure over a considerable period of time, preferably longer than 5 seconds. This thus maintains the protection for the vehicle occupant even when the vehicle topples.
In one preferred embodiment of the invention the vehicle door comprises a windowsill and the gas bag is supported along the majority of the windowsill, this large supporting surface area of the gas bag on the windowsill ensuring enhanced stability. It is good practice when the gas bag is fabricated to extend far up to the front side of the door to prevent the hands of the vehicle occupant from being catapulted outwards from the vehicle. For this purpose the gas bag is shaped so that particularly the forward window area is covered practically completely, thus also enabling the gas bag to gain maximum possible stability from being supported at the A-pillar and windowsill. Preferably the gas bag extends likewise up to the vehicle rear end of the windowsill to also provide head protection for the vehicle occupant.
In a further preferred embodiment of the invention the gas bag comprises two chambers, the first, outer chamber of which is configured tubular and has a high internal overpressure and the second, inner chamber is cushion-shaped and has a lower internal overpressure, the first, outer chamber surrounding the second, inner chamber. The outer chamber forms a stable frame due to its high internal overpressure endowing the gas bag with the necessary stability and by which the gas bag is supported at the A-pillar and at the windowsill. The inner chamber is configured as a cushion having a lower internal overpressure so that a vehicle occupant catapulted into the gas bag does not rebound therefrom but is softly cushioned therein. It is in this way that the necessary stability can be combined with the necessary pliancy of the gas bag. Preferably, the outer chamber and the inner chamber are not in flow connection with each other. Thus, the frame formed by the outer chamber retains its stability during the entire time the gas bag is inflated.
In the folded condition the gas bag can be accommodated in the windowsill or in the A-pillar.